This invention relates to control of an arrangement of data on a cache of a service server.
In recent years, nonvolatile memories (NVM) such as a flash memory are used in various electronic devices. Unlike a hard disk drive (HDD), the nonvolatile memory does not involve a mechanical operation, and enables faster access than the HDD.
Nonvolatile memories are also used in enterprise applications such as a server and a storage system that need fast data access. In particular, nonvolatile memories mountable in servers become inexpensive, and are thus becoming popular.
As the related art, there is known a system in which a flash memory is used for a cache memory different from a main memory. For example, refer to US 2009/0024793 A1. In this case, based on access characteristics (such as an access frequency) of data, a cache driver included in an OS or the like operating on a server stores cache data in the flash memory, and ejects cache data from the flash memory. As a result, a high-speed data access can be realized.
Moreover, as related art, there is known a technology for a storage system, in which a hierarchical storage area is constructed from a storage medium with high an access performance and a storage medium with low access performance, and the storage area for storing data is changed based on access characteristics of the data. For example, refer to JP 2000-293317 A.